Satellite radio advertising revenue is forecast to increase 62.3 percent to $225 million in 2010, according to PricewaterhouseCoopers' annual entertainment and media outlook. By contrast, terrestrial radio advertising is forecast to rise on an average of only 4.2 percent a year to $24.4 billion in 2010.
By 2010, PwC is projecting that the number of satellite radio subscribers will reach 30 million.
[Billboard Radio Monitor]
By 2010, PwC is projecting that the number of satellite radio subscribers will reach 30 million.
[Billboard Radio Monitor]

"By contrast, terrestrial radio advertising is forecast to rise on an average of only 4.2 percent a year to $24.4 billion in 2010."
only 4.2% is over a Billion dollars
There's no doubt that Terrestrial makes a lot of money. Absolutely.
But remember that radio's primary source of revenue is from advertising, where as satellite radio the lionshare of their revenue from subscriptions.
From the same report: satellite radio revenue is expected to grow 39.5 percent to $5.4 billion in 2010 - with $5.2 billion coming from subscribers.
This info is slightly misleading.
Satellite Radio
To increase 62.3% in 5 years.
(10.2% per year)
Terrestrial Radio
To increase 4.2% per year over 5 years.
(22.8% in 5 years)
Still better news for satellite radio, but you should really compare apples to apples not apples to oranges.